Software effort estimation is critical for resource allocation and planning. Accurate estimates enable managers to distribute the workload among resources in a balanced manner. The actual workload of developers may be different from the values observed in project management tools. In this research, we provide a summary of our experiences regarding: a) effort estimation activities, b) the developer workload distribution through churn data and c) a method of using churn data to track estimation process. Our experience report depends on our collaborative work with our industry partners operating in various domains in Turkey. As a result, we observe that effort estimation is taken as an important topic. However, there is a large space for research to transfer the ad-hoc methods employed in industry to empirical ones. Interestingly, we observe that resource allocations based on initial estimates/plans do not conform to actual values. The common characteristic of developer contribution in different projects is: More than 80% of edits in code are performed by a small number of developers.